This invention relates to door mechanisms particularly designed for use on conical hoppers or other locations where the door will open in a downward direction.
Manholes or clean out ports are common in various vessels. If such a clean out port or manhole is placed on the down side of a conical hopper, once the latch mechanism holding the door locked in place is removed, gravity will cause the door to swing freely down. If a maintenance person is in the area, this swinging door may cause physical harm to that maintenance person by swinging open more rapidly than anticipated and because of its weight may cause severe personal injury.
While a door can be made out of light weight material, in many applications it is not practical to use a light weight material and even if it is practical, the door will still swing open on its own.
It would be desirable to provide a simple mechanism for limiting the free movement of the door in a downward direction.